1. Field
The disclosure relates to a wireless communication method and apparatus. More particularly, the disclosure relates to a method and apparatus for simultaneous communication utilizing multiple wireless communication systems.
2. Background
Wireless communication devices generally operate in either licensed radio frequency (RF) bands or unlicensed RF bands. Wide area network (WAN) providers generally acquire licenses to operate wireless communication systems in one or more of a plurality of licensed RF bands. These systems employ methods that allow multiple accesses by mobile stations on a common band of frequency channels. These systems generally operate in licensed RF bands. Other systems operate in unlicensed RF bands. Systems that operate in licensed RF bands have control over the transmissions in the licensed frequencies and channels. This allows the operator to ensure reliability of data, and in particular, control information used for control channels and link maintenance and establishment. Systems that operate in unlicensed RF band do not have this control and data transmission errors may occur as a result of uncoordinated transmissions by different users and service providers.
One access technique for WAN is frequency division multiple access (FDMA), which allows multiple access by assigning the mobile stations to different frequency channels within the RF band. Some of these systems employ frequency hopping, wherein data is transmitted to and from the intended mobile station while periodically changing the frequency channel. The periodic channel frequency hopping occurs on a regular time interval, e.g., a frame. Coordinated frequency hopping systems use predetermined hopping patterns, or hop-sets, where the hop-sets are coordinated between all mobile stations to ensure that the signals to and from two or more mobile stations do not occur simultaneously on the same frequency channel. Uncoordinated frequency hopping does not coordinate the hop-set between mobile stations resulting in the periodic occurrence of simultaneous signal transmission on the same frequency. Such simultaneous transmissions are referred to as channel collisions. Data reception errors occurring during a channel collision are referred to as data collisions. Uncoordinated frequency hopping within this type of system is generally not used as the channel collisions and resultant data collisions may occur. The FCC has prohibited coordinated frequency hopping within the Industrial Scientific and Medical (ISM) bands in order to avoid spectrum aggregation by a single type of service. Systems such as Bluetooth and 802.11 Wireless Local Area Networks (WLAN), for example, operate within the ISM bands.
Another type of WAN is a code division multiple access (CDMA) system, Global System for Communications (GSM), or a Wide Area CDMA (WCDMA) system. These systems utilize different codes for differing users to allow multiple access to prevent collision between signals of different mobile station users.
Systems, such as 802.11 WLANs, generally have very high data rates when compared to systems that operate within a licensed RF band. However, the likelihood of collisions with respect to data and control signals in 802.11 WLANs is higher when compared to WANs.
With an increasing demand for improved wireless communication devices, there remains a continuing need in the art for a method and apparatus that prevents collision between signals of different mobile stations while allowing for high data rate transfer.